android4.2上获取应用程序大小的变更点
PackageManager.getPackageSizeInfo(String packageName, IPackageStatsObserver observer)不可用，改为PackageManager.getPackageSizeInfo(String packageName, int userHandle, IPackageStatsObserver observer), 至于增加的参数userHandle的解释是：The user whose size information should be retrieved。下面是PackageManager内部的用法：
private void getPacakgeStats(String pkgName) { if (pkgName != null) { try { Method getPackageSizeInfo = mPm.getClass().getDeclaredMethod("getPackageSizeInfo", String.class, int.class, IPackageStatsObserver.class); /** * after invoking, PkgSizeObserver.onGetStatsCompleted() will be called as callback function. <br> * About the third parameter ‘Process.myUid() / 100000’，please check: * <android_source>/frameworks/base/core/java/android/content/pm/PackageManager.java: * getPackageSizeInfo(packageName, UserHandle.myUserId(), observer); */ getPackageSizeInfo.invoke(mPm, pkgName, Process.myUid() / 100000, new PkgSizeObserver()); } catch (Exception e) { Log.e(TAG, e.toString()); } } }